Growing olives organically

Organic growing is when your system emulates nature in its interconnectedness. It tends not to rely on massive amounts of plant protection or highly manufactured fertilizers and it has minimal impact on the surrounding environment. Spinoffs of organic growing are that you can be sure no toxic residues remain in fruit when it is harvested and that youre eating food produced by a sustainable system. Premium prices are another reward; they can add 30-100% to the value of your crop.

Choosing varieties is a key step towards organic growing

Get varieties which do well in your area and have been bred for disease and adaption to the environment. We use the table olive variety UC13A6 rather than Sevillano because of its easy pollination, regular cropping and tolerance of less than perfect soil fertility. Mission is a variety which withstands cold and produces a dual purpose olive.

Plant trees which ripen at a convenient time for harvesting in your area and dont require abscission-promoting chemicals to be used for mechanical harvesting (Manzanillo may be tough to harvest). Go for varieties which are going to sell readily, remembering that organic buyers are also often gourmet buyers, and are seeking food with a lot of character. Be very clear that most table olives produce very little oil. Good information about yields is available and I was surprised to see how well an old variety had done in national trials. Del Marocco had been saved from a 1903 planting by Prof Arthur Perkins at Roseworthy and propagated for new plantings by Olives Australia.

Certified organic

If you wish to have your olive products certified organic you can choose between the National Association for Sustainable Agriculture Aust (NASAA), Biological Farmers of Australia (BFA) or Biodynamic Farmers Association (who use the Demeter brand). These organisations can provide information and arrange for a property inspection and soil/produce tests to ensure that you are not growing your olives on a contaminated site or receiving non-allowed sprays via wind drift from neighbouring properties. Their certification is accepted by the Australian Quarantine Inspection Service as the basis for Australian organic exports and guarantees freedom from canola or non organic oils.

Soil & fertiliser

Olives are tolerant of sites which are marginal for most horticultural crops but even they baulk at a layer of solid rock or an impermeable clay. Areas with very shallow water tables are not the place to plant olives.

Provide the tree with certified organic fertilizer on a regular basis and keep an eye on your trees for any signs of nutritional problems: small or malformed leaves, mottling, excessive lightness in colour, or poor quality fruit. Such symptoms can give an indication of nutrient deficiencies which may be corrected by applying a dose of an appropriate organically approved compound. Undertaking soil or leaf tissue testing is recommended for substantial plantings. Some analytical labs are happy to prescribe organic fertilizers. We use an independent lab called SWEP, 47 Bridge Rd Keysborough Vic 3173. The organic certification organisations can provide you with a list of allowable fertilizers and the regulations for their use if you wish to sell produce as organic.

Whilst compost is used to replace the bulk of the nutrients lost when fruit leaves the property, leguminous inter-row plantings like sub clover or Faba (Broad) beans help with Nitrogen fixation from the atmosphere. Wood ash is often a useful fertilizer (used in moderation) to help with the olives high need for Potassium and there is a good chance youll need to apply zinc.

Weed control

Organic weed control methods include mowing, mulching, flame weeding, steam weeding, timely cultivation and green manuring. The addition of animals may also provide a boost to income.

Geese are excellent as weed controllers; they are soft footed and compatible with well established tree crops. They clean up significant quantities of weed seeds as well as consuming herbage, mainly of grass species; they can control Couch Grass effectively. In Southern Australia the Christmas Goose market fits well with feed availability. Sheep are good at eating down young Salvation Jane but can do significant soil and tree damage if used at inappropriate times. We use Brush Tailed Bettongs to control sour sobs and they pose no risk to the trees or the soil.

Some people would say that the Olive is itself a weed as it has successfully invaded many higher rainfall areas and creek lines. It is essential to harvest the fruit thoroughly and as early as practicable and for olive growers to practice reasonable bird control (if it is needed) to stop birds taking your olives all over the countryside.

Irrigation

The olive is magnificently adapted to Southern Australia and that is one of its major benefits in designing a sustainable food production system. In a well-designed orchard it will produce crops with low inputs; to turn it into a fully irrigated, super fertilised crop seems to defeat its adaptive advantage over softer species. However a dryland/supplementary irrigated tree needs to find a stable relationship with the soil block it is exploiting and excessive competition for moisture between it and other trees must be avoided if the tree is to produce reasonable crops. The tree is not going to produce masses of new growth every year, just enough to produce the crop. Once in balance with its environment, the tree almost stops growing - putting a great deal of effort into forming fruit, so only minor pruning is required.

However some watering is vital in areas receiving under 600mm of rain if you are to obtain good crops of high quality fruit. Permanent sprinkler systems are a nightmare for organic growers as the overhead systems promote fungal problems and pests and the under-tree sprinklers seem to fall prey to mowers and become buried in weeds. Suspended drip lines enable the use of mowers and the wetting pattern of drippers is not interfered with by weeds.

We apply about 1000 litres of water per tree per annum in addition to the 450mm rainfall (less than 5% of a conventional irrigation regime), much like the Spanish, and in this rainfall area I believe trees should have a spacing of no less than 6 metres by 6 metres to give them a reasonable soil block to exploit for moisture and nutrients. In a higher rainfall area (600-1000mm) I would still put in the irrigation system for establishing the trees and for applying water in particularly low rainfall years.

Pest control

Pest and disease control are minimised by building diversity into your property.

Foragers such as chickens are invaluable in controlling insect pests and can eliminate the need for insecticidal spraying. They are an effective predator of Curculio Beetle, the weevil that chews those scallop shapes in your olive leaves. If weed or pasture growth is rank, chooks are not effective so mowing the tree lines is a good strategy.

Many insect problems can be resolved by spraying the trees with Light Mineral Oil or Vegetable Oil; this is an organically acceptable way of suffocating the adults and eggs of pests such as the Black Olive Scale (also known as Brown Scale); a 2% oil spray is applied in Dec/Jan when the young have hatched. A major problem in building up good ecological control of scale is that ants farm the scale for the sugary substance they exude and protect the scale from natural enemies such as parasitic wasps and the larvae of lacewings, black ladybirds etc. A non-biocidal solution to the ant problem is to install sticky bands around the tree trunks. This stops both the ants and Curculio beetles. In SA a goo called Tak Gel (from Rentokil) is excellent. It is pasted onto masking tape wrapped around the trunk. Branches touching the ground will of course negate the usefulness of the band!

Organisations and resources available for olive growers

Olives SA - Functionally the Olive Association of South Australia - runs seminars, tastings, field trips and has a coordinating committee which meets regularly.

Olives Australia - A major nursery located in Qld. They have a staggering range of varieties (50+) and send trees all over Australia quite cheaply.

Australian Olive Association - An association with individual members from all over Aust. It has successfully collaborated with regional organisations despite a slightly bumpy take-off in 1995. Publishes The Olive Press newsletter and coordinates seminars, overseas guest expert visits etc; is the national political voice of the olive industry.

Primary Industries and Resources SA - This government department has been heavily involved in the establishment of Olives SA. They provide a development and extension service through their specialist consultant Susan Sweeney, Rural Solutions SA based at the Waite campus. They have produced an Excel spreadsheet package for calculating Gross Margins and constructing Development Budgets as well as publishing good written material.

Pickling & packing

Top up salt concentration after a 6 weeks to bring it back to 10% (which equilibrates to a Specific Gravity of about 1.06)

Regularly top up any solution lost through bubbling over as a result of ferment

Pack after 6-9 months (Green olives may take 12 months)

Containers

We have found that second hand pickle plastic barrels can be readily purchased from salvage establishments or olive wholesalers who repack imported olives for sale. The barrels are not completely airtight, so allow CO2 to escape during the fermentation process  which is an advantage. The barrels also often come with a lid with a small central screw port which can be opened to top up the brine. A real bonus is when you find barrels with plastic submerging screens that hold the olives well under the brine. If air is allowed to enter the barrel, a white surface yeast will probably form; this causes the olives to go soft, so keep the vessel topped up with brine so there is no airspace. 200 litre and 60 litre barrels are available.

If doing small quantities one can keep the surface of the brine free of air by covering it with a plastic bag full of water.

Processing with brine

Clean olives are placed directly into brine (10% w/v food-grade sodium chloride in potable water) [sea water can be used] where over time they take up salt and undergo a weak fermentation. The pH of thebrine should be corrected by the addition of a food acid such as citric acid to achieve a maximum of 4.5 - if salt levels are lower than 10% acidify to 4.0-4.2.

After 6 to 8 weeks the salt in the brine equilibrates with that in the fruit and should be maintained at around 8 to 10% during processing. During brining, water-soluble oleuropein and other phenolic compounds, sugars, vitamins and minerals leach out of the olive flesh, The net result is debittering of the olives. During fermentation sugars are converted to lactic and acetic acid, alcohol and other substances which contribute to the taste of the olives. Processing takes at least 3 months and up to 12 months depending on the variety, maturation level of the fruit, temperature, salt and pH levels of the brine. Green- ripe olives take longer to process than naturally black ripe olives.

Slitting or bruising the olives, particularly green-ripe ones, speeds up the debittering process. Advantages of this method are its simplicity and that it requires only water for initial washing and fermentation, particularly if the fermentation solution is used as the final packing solution. The major disadvantage is the processing time.

After processing the olives can be packed in either the fermentation brine, in new brine or a combination of the two.

Green-ripe olives processed by this method gives products similar to Greek style green or Sicilian style olives. Flavours can be further altered by adding herbs spices and aromatics eg lemon, garlic and oregano or mixed herbs, mustard seed and chilli. Naturally black ripe olives processed by this method give the traditional Greek style black olive. Adding red wine vinegar and olive oil to Greek style black olives gives a product similar to Kalamata style olives. We prefer to use a vinegar/brine mix to drop the saltiness a little.

Packing with brine and vinegar

Make up a 10% (w/v) brine solution (a 7-8% brine can also be used if the 10% brine is considered too salty).

Use 3 parts of this brine and add 1 part of vinegar of choice (5% acetic acid is standard)..

Pack the olives in the containers eg bottles and add the brine/vinegar solution nearly to the brim of the container.

Add a layer of oil enough to cover the surface of the solution.

Seal the container, label and store in a cool place

Different styles of vinegar will obviously add different flavours to the olives.

Lighter coloured vinegars are generally used with green olives whereas coloured vinegars are used with black olives. Olive oil is the preferred oil to be added, although other seed oils eg canola, high oleic sunflower oils are used when the olives are to be stored under refrigeration

Desalting olives

If wanting to 'desalt' olives, cover them with hot water (at least three times as much water as olives). Let stand about four hours, ideally in the refrigerator. Repeat as required to taste. If wanting to store the olives keep in the fridge in a weak vinegar solution (1 part water to 3 parts commercial vinegar) for a week or so.

Other methods

The following pickling recipes article has been adapted from Australian Olive Grower Issue 4, November 1997.

Place the olives on a clean stone surface or cutting board and bruise them with another stone or hammer. Alternatively prick several times with a fork, or make three slits in the skin of each olive with a small serrated knife while turning the fruit between the thumb and index finger. This bruising, pricking or cutting will allow the water and salt to penetrate the fruit thereby drawing out the bitterness and also preserving it. This will also do away with the need to use a caustic soda solution as used in commercial processing of olives.

Toss them immediately into a bucket of clean water in which one half cup of coarse or cooking salt has been dissolved into every ten cups of water. A clean plate can be placed on top to keep the olives submerged. All olives must be under the liquid. Pour the liquid away each day and replace with fresh salt water. Repeat this washing process for about 12 days for green olives and about 10 days for black (ripe) olives. The best test is to bite an olive. When the bitterness has nearly gone, the olives are ready for the final salting. As you can see, this simple recipe involves the disposal of salty rinse water into the environment. If you decide to commercially pickle olives, there are other recipes that require a longer pickling time but do not result in salty waste water.

Pour off and measure the last lot of water so you will know the volume of salt brine that will be required. Measure that quantity of fresh, warm water into a pan and dissolve the salt, this time at the rate of 1 cup of salt to 10 cups of water. Bring the salt water preserving mixture to the boil and allow to cool. Place olives in bottles and then pour the salt water brine over them until the fruit is completely submerged. Top up the bottles with up to one centimetre of olive oil to stop air getting to the fruit and seal the lids on. No further preparation is required and the bottled olives will store for at least 12 months in a cool cupboard.

When you are ready eat your olives, pour out the strong preserving solution and fill the jar with clean, cool water. Leave in the refrigerator for 24 hours and taste them. If they are still too salty for your liking, then refill the bottle with a fresh lot of water and return to the refrigerator for a further 24 hours. (The plain water leaches some of the salt back out of the olives). At this stage you can also add any or all of the following flavourings: Grated garlic, basil, oregano, chopped onion, red capsicum, lemon juice and lemon pieces. Especially popular is a combination of garlic, basil and lemon juice.

Black olives in dry salt

This is a traditional way of producing olives. Alternate layers of washed black olives (5cm) and salt (1cm) are placed in a container containing drain holes in its base; it should not be made of metal as the salt would attack it - plastic crockery or earthenware are fine. You can simply use a plastic bucket with quarter inch holes drilled through the bottom. The container is covered and left in a dark place. Shake after a day. Over about 4-5 days osmotic pressure causes the olive fluids to drain out of the olive while salt dissolves into the olive.

The strong salt tends to debitter the olive and eventually equilibrium is reached with most of the olive fluid having been removed and an acceptable salt level reached. If you still consider the olives too bitter, add some more salt on top of the olives, shake and leave for a few more days. The whole process should be over in 10 days.

Olive juice will seep out over all this time so make sure you catch the brine that drips from the container. Don't let the bucket sit in the accumulating brine.

The olives will be wrinkled and whilst intensely 'olivy'; they are almost sweet too.

When the olives are to your taste, wash thoroughly in fresh cold water until all salt is removed.

Then they can be dried (a low heat oven or a home dehydrator is often used if you wish to simply have dried olives). The olives can also be stored in olive oil, in jars or alternatively put in zip-lock bags and kept in freezer until you need them. Olives will keep for years in the freezer and should be thawed naturally.

Others put olives in 50:50 oil and vinegar (oil, vinegar and herbs of your choice and vinegar of your choice) in glass jars.

Recipes

'Ash and Olives!' by Craig Hill

Crush and sift a quantity of new wood ash; the weight of the ash should be equal to the weight of the olives to be prepared. The olives should be freshly picked, clean and undamaged.

Make a fairly liquid paste by pouring boiling water on the ash. Cover and allow to cool completely.

Carefully stir in the olives to coat them with the ash paste.

Gently stir the olives once daily for 5 to 7 days.

Towards the end of the week, cut several olives lengthwise; the "de-bitter-isation" is complete when the fruit has darkened to about 1mm from the stone.

Rinse the olives clean [dispose of the ash paste and contaminated water thoughtfully] and submerge them in clean water (avoiding contact with the air); the water should be changed every 4 or so hours for the first day, then daily for 3 or 4 more days. This process is finished when the water remains clear and has no or little rusty discoloration. [At this stage you should also taste the fruit: although the flavour will be rather crude, the bitterness should have all but disappeared.]

Preserve in sterile jar(s) in a saline solution or vinegar mixture as in the usual recipes, adding aromatic herbs, garlic, lemon pieces to taste and with a 5mm layer of olive oil.

The concentration of the preservative/saline solution in point 7 should be sufficient to partially float an egg or a small potato. Personally I err on the generous side with the salt (thinking that the olives are doing me so much good that the body can probably tolerate a bit more salt!). Depending on the aromatics, I've usually added about 10% vinegar. An Italian contact also taught me the trick of keeping the olives submerged by placing a 'wreath' of wild fennel stalks under the lid.

An unusual method but with a sound explanation! Wood ash is about as alkaline as the usual soda/lye recipes and this neutralises the oleopicrine. The advantage of this "alkaline" bath is that, done properly, it preserves the integrity ie the flavour, firmness and colour of the fruit. The advantage of this method is that it 'appears' to be a bit more environmentally friendly than using caustic or washing soda. There is still the problem of disposing of the strongly alkaline paste, but it seems to be less environmentally disastrous than some other methods.

Here's another recipe from Kymira Olives, Karrinyup, WA

Place the olives on a cutting board and bruise them with a stone or hammer. Alternatively, prick several times with a fork, or make three slits in the skin of each olive with a small serrated knife while turning the fruit between the thumb and index finger. This bruising, pricking or cutting wil allow the water and salt to penetrate the fruit thereby drawing out the bitterness and also preserving it. This will do away with the need to use caustic soda solution as used in commercial processing of olives.

Toss them immediately into a bucket of clean water in which one half cup of coarse or cooking salt has been dissolved into every ten cups of water. A clean plate can be placed on top to keep the olives submerged. All olives must be under liquid. Pour the liquid away each day and replace with fresh salt water. Repeat this washing process for about 12 days for green olives and about 10 days for black (ripe) olives.

The best test is to bite an olive. When the bitterness has nearly gone, the olives are ready for the final salting. As you can see, this simple recipe involves the disposal of salty rinse water into the environment.

Pour off and measure the last lot of water so that you will know the volume of salt brine that will be required. Measure that quantity of fresh, warm water into a pan and dissolve the salt, this time at the rate of 1 cup of salt to 10 cups of water. Bring the salt water preserving mixture to the boil and allow to cool. Place the olives in bottles or jars and then pour the salt brine over them until the fruit is completely submerged. Top up bottles with up to one centimeter of olive oil to stop air getting to the fruit and seal the lids. No further preparation is required and the bottled olives will store for at least 12 months in a cool cupboard.

When you are ready to eat your olives, pour out the strong preserving solution and fill the jar with clean, cool water. Leave in a refrigerator for a further 24 hours (the plain water leaches some of the salt back out of the olives). At this stage you can also add any or all of the following flavourings: basil, grated garlic, oregano, chopped onion, red capsicum, lemon juice and lemon pieces. A popular combination is garlic, basil and lemon juice.